Quantitative analyses of DAPK1 methylation in AML and MDS

Abstract

Aberrant DNA methylation and concomitant transcriptional silencing of death-associated protein kinase 1 (DAPK1) have been demonstrated to be key pathogenic events in chronic lymphocytic leukemia (CLL). In acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), however, the presence of elevated DNA methylation levels has been a matter of continued controversy. Several studies demonstrated highly variable frequencies of DAPK1 promoter methylation by the use of methylation-specific PCR (MSP). By quantitative high resolution assessment, we demonstrate that aberrant DNA methylation is an extremely rare event in this region. We observed elevated levels just in one out of 246 (0.4%) AML patients, all 42 MDS patients were unmethylated. In conclusion, we present a refined DAPK1 methylation analysis in a large representative patient cohort of AML and MDS patients proofing almost complete absence of elevated DNA methylation. Our results highlight the importance of quantitative measurements particularly for translational research questions on primary patient specimens.

Extensive Promoter DNA Hypermethylation and Hypomethylation Is Associated with Aberrant MicroRNA Expression in Chronic Lymphocytic Leukemia

“…Quantitative DNA methylation was measured using the MassARRAY system as previously described (30). Primers are given in Supplementary Table S2. miRNA expression microarray analysis miRNA expression arrays using BeadArray technology and Human v2 miRNA arrays were processed according to the manufacturer's instructions (Illumina).…”

Despite differential gene expression profiles pediatric MDS derived mesenchymal stromal cells display functionality in vitro

“…In addition, increased CRLF1 in combination with IL-6 has been described in idiopathic pulmonary fibrosis causing inflammation, but suppression of fibrosis (Kass et al, 2012). DAPK1 down-regulation, associated with malignant transformation, has been described in the hematopoietic cells in adult RAEB(t)-MDS potentially attributing to aberrant methylation (Raval et al, 2007;Qian et al, 2010;Wu et al, 2011;Claus et al, 2012;Karlic et al, 2013). We demonstrate a similar expression profile in our MSCs, with expression in RCC-MDS being similar to HC-MSCs, and down-regulation in RAEB(t)-MSCs.…”

DNA Methylation Abnormalities in Hematopoietic Disorders: Biological Significance and Methodological Approaches

“…In conclusion, there has been a vast expansion of high-throughput quantitative assays, in particular pyrosequencing and MALDI-TOF enabling more reliable high resolution, quantitative DNA methylation analyses in large sample sets (Claus et al 2012a ).…”